Conventional passenger conveyor systems, such as mechanical stairs or moving walkways, include a chain of conveyor plates or steps moving in a circuit for the purpose of providing a continuous movement along a specific path. The conveyor plates or steps are connected to said chain circuit, which chain acts moved by a drive system. The drive system normally consists of a chain of conveyor plates, gear wheels, a shaft and an electric motor. The electric motor drives the shaft to which the gear wheels are integrally joined, which wheels transmit a movement to the links of the chain of conveyor plates or steps. Whenever the links of this chain move, the conveyor plates or steps move in the same way. The drive of the handrail in a conventional moving walkway or mechanical stairs takes power from the shaft to which the gear wheels driving the chain of conveyor plates or steps are integrally joined and drives, by means of several traction members, a wheel moving the mentioned handrail by friction.
To assure a small speed fluctuation and minimize the polygonization effect in a conventional conveyor system, a large number of teeth are required in the drive wheel and this gives rise to a large diameter increasing the size of the upper and lower heads of the system, making a very deep pit for locating the walkway necessary. The link between the plate and the chain of conveyor plates is conventionally located under the surface of the plate. Given that the gap between two consecutive conveyor plates is closed for safety reasons, the transition radius in inclined walkways must be limited.
Other types of drive mechanisms have been proposed which engage the belt at intermediate points such as those disclosed in U.S. Pat. No. 3,677,388, Int. Pat. WO2004/063078A1 and WO2004/054919A1. The common point of all the aforementioned inventions is that all of them propose using a linear drive system to move any type of chain joined to the conveyor plates or steps and, therefore, to drive the chains of conveyor plates or steps of the conveyor system. Nevertheless, the contact of metal with metal between the chain of the linear drive system and the links of chains joined to the conveyor plates or steps generates noise. The general configuration proposed in these documents does not allow reducing the dimensions of the walkway either. The general dimensions of conventional walkways are much larger than those that the present invention can offer.